This Genesis Illustration is from the Huntington Library, San Mario, California.
You can read more about it in The Traveller in the Evening: Last Works of William Blake by Morton D. Paley.
Blake was working on illustrations to the book of Genesis during the last two years of his life; remaining are eight incomplete pages. One of the alternative title pages is shown in the link. It seems that near the end of his life Blake was making an effort to bring together graphically the characters in his own myth and the players in the Biblical story.
Damon in A Blake Dictionary (page 151) had a go at describing what Blake's imagination has produced:
"In the more elaborate sketch, the Father and son appear according to tradition, while the Holy Ghost is a nude youth. On the left is Christ with arms extended in the cruciform position, but he is not suffering. From his left hand a scroll descends, which reaches to the uplifted right hand of the Holy Ghost. On the right counterbalancing the Son, is the Father, who stands on a black cloud and points upward to another; behind his glory, black flames are just peeping out."
"In a row beneath sit the Four Zoas, represented as the four beasts. On the far left is Luvah, as Orc turning into the Serpent. Crowned with gems, snake-tongued, laughing, he uplifts his left hand toward the apple tree above him. He is the only active Zoa; the other three apparently have their hands folded in prayer. The second is Urthona-Los as a eagle with a crown; he inclines toward Luvah-Orc but turns his head away. Urizen as a lion draws away from the eagle. Last is Tharmas as a horned ox; above him is the fruit-laden tree of life."
Although I am glad to have the the commentary of Damon, I see some of the images differently. The running man at the top of the picture I take to be Urthona-Los as the Holy Spirit. The central figure whom Damon identifies as the Holy Ghost, I take to be Adam-Urizen (in his unfallen state). As Adam he is the first born of humanity, as Urizen the 'first born son of light.' (Four Zoas (E 108)). Jesus, identified as the Son, is seen in terms of the Zoas as Luvah, since the Lamb of God was clothed in Luvah's Robes of Blood. Damon says of Tharmas: "As an aspect of Deity, he is the first Person of the Trinity, the ever pitying Father, but also the good shepherd." So we have all four Zoas represented in the upper image as well as in the lower.
It is unfortunate that we don't have a really clear or completed image of the picture because Blake was trying to pack so much information into one picture, summing up much of what his imaginative powers had discerned through a lifetime of thought, work and vision.
Song of Los, Plate 3, (E 67)
"Adam stood in the garden of Eden:
And Noah on the mountains of Ararat;
They saw Urizen give his Laws to the Nations
By the hands of the children of Los."