The cover artist for the 1987 and 1991 Ace editions of "Stranger in a
Strange Land" was James Warhola, the nephew of Andy Warhol.
"Stranger in a Strange Land (Ace 0-441-78838-6, Oct ?91 [Sep ?91],
$9.95, 525pp, tp, cover by James Warhola)"
Locus Magazine: The Locus Index to Science Fiction
Two online images:
Um Toque de Arte: James Warhola Stranger in a Strange Land
Audart Gallery: Stranger in a Strange Land by James Warhola
If you are interested in purchasing a print, you may want to contact
the artist and/or the Audart Gallery.
You can email James Warhola at this address:
The Audart Gallery may be contacted at this address:
My Google search strategy:
Google Web Search: "stranger in a strange land" "james warhola"
I hope this is precisely what you need! If anything is unclear or
incomplete, or if a link doesn't work for you, please request
clarification; I'll be glad to offer further assistance before you
rate my answer.