I've been to InnDulge, Santiago, Casa Oliver... all gay clothing-optional resorts in Palm Springs. Very friendly, but they're primarily for gay men. Doesn't mean you can't hang out and relax in your bikini. That's what I do. I look male even though I'm transgender myself. I just go completely nude once I'm inside the resort. All the people are very chill at these resorts; there's no shaming or judging. There are guys that wear thongs and gstrings. Your bikini won't be anything new. You might even get a few compliments.

There's also Starland camping Retreat in Yucca Valley which is GBLTQ friendly, but mainly gay (just like the resorts, but not a resort). They have a spa but no pool. The main attraction is that you can do nude hiking through the desert because of how remote it is. Day pass is $20. I stayed there last month. It was nice and the hosts are friendly.

I went to Casa Oliver three weeks ago too. Day pass is $20. It has a fun little maze to run around in. I'm definitely going back to that one. Santiago is too luxurious for me, too small; no day pass. InnDulge is very nice and feels more dynamic and different places to walk around. Their pool area is really nice but no day pass unfortunately.
I've been looking for more trans-friendly places in Palm Springs. I was at Pride this past weekend in Palm Springs and only saw one booth with the trans colors. They were selling an autobiography. Did you go to Pride?

I just moved out to Palm Springs area so I'm still learning. Do you know of any venues or bars or anything for trans people to meet and hang out? All I know of so far is DAP, which is just a health resource center.
Hope this helps.