Its probably suffering from transplant shock. Put it in partial shade, keep its regular watering schedule and don't feed till it perks up. Don't feed stressed plants, the roots can't take up food, they're to busy keeping the plant alive.
If the plant was inside and moved outside into bright sun in one trip with being hardened off it could be in shock from that and being transplanted. When transplanting a container plant its best to keep it in its new pot and the same location until it gets established. To move an indoor plant outside it needs to be acclimated over a week or two.
Reverse the procedure if moving the plant back indoors over the winter
