You could offer it on here for the price of shipping, letting people know it's a rescue etc.

You could find any local rescues that take in reptiles.

You could find any local(semi-local) reptile clubs/herping clubs and see if anyone wants it(enthusiasts will drive amazing distances to get a specimin they particularly would like to keep).

You could contact any seller/vender you trust and ask if they'd be interested in it.

You could sell it yourself either locally or via shipping.

Since they gave it to you, you're under no obligation to keep it forever. It's now in a responsible person's hands, and I'm certain there's folks out there that would leap at the opportunity to keep that particular lizard.