This book was first published in 1963. Dallas Mayo was a pseudonym for Gilbert Fox, who was the founder of Midwood Books. Midwood Books published “adult” reading.
On many sites, this cover is credited to Paul Rader, who did do quite a few covers for Midwood Books. However, I’ve also seen a lot of comments from people saying that Rader didn’t actually do this cover. It looks like Rader’s work to me but I’ve seen enough differing opinions that I’m not confident crediting this to anyone. If you know who did this cover, let us know in the comments!