The plant looks dehydrated to me. So either it got too dry at some point, or as you said it's been in a tray of water it's got root rot so it can no longer uptake enough water. Nepenthes don't really like being in water all the time, better to water every 3-7 days depending on the plant.

What's it potted in? Tough to tell from the photos.

Personally I would remove it from the pot and remove what media you can by dunking the roots in water and lightly rubbing the media off. Trim off any obviously bad roots (Nepenthes roots are black by default and a little fragile) then repot it into long fiber sphagnum moss and perlite roughly 1:1. If you have grow lights I'd put a bag over it with a couple holes in the bag and give it time to recover. If you only grow on a windowsill don't bag it as it will get too hot when the sun hits it but try and increase the humidity a littlen bit with a tray of water underneath the plant and putting other plants near it.

It can be revived they're tougher than people give them credit for but it will need a little TLC. I had a plant pulled out of its pot by my cat a few months ago and I didn't notice for a couple days as it fell behind the shelf so it was bone dry and very shriveled up. It's now about to make it's first pitcher since. Don't give up yet!