It seems like you are using a fairly old model, so getting it very realistic is not easy I think. If you are talking about cloth mesh it self and you have access to changing it, it looks a bit to bulky at the top around the upper arm and shoulders. Also simply by adding textures to the cloth maybe just a uniformed black fabric could help, you can find some just by doing a search on black fabric on google. Also the highlights on the cloth is only something you would see on latex etc, so i if it should be cotton or something you have to remove it.

If you have access to Poser cloth room, I can make you a pair of pants and jacket which you can then simulate if you want?