My three year old daughter did something very similar at her new daycare. She loves the new kids and what she is learning but nap was not happening. She would come home and cry about naptime.
She slept wonderfully at the old daycare and at home, but this new daycare naptime became a challenge for about a month. She would do several different things during the naptime, including lay quietly, screaming to wake the other kids up, and wondering around till she found the daycare provider. The daycare provider would keep us posted on her behavior during nap time and we would reward her at home with small things she was interested in (such as Halloween window decorations). When she was slept, she was rewarded.
We also brought her favorite two blankets and her dino to sleep with. It helped a little. We now do not need to bring any of her home comforts. She is now sleeping 1 1/2 hours regularly. I do not know what was the trick that worked, the passing of time or the small rewards, but we no longer have the issue.
Good luck!