Graphic cards that are meant for desktop PC like a Radeon HD 7750 or GTX 560 cannot fit in a laptop. Laptop graphic cards uses the MXM format which are tiny compared to desktop graphic cards.
The vast majority of laptops (98%+) do not allow you to upgrade the graphic card. The ones that do are typically expensive gaming laptops ($1,500+), but only certain models of gaming laptops will allow you to do so.