You cannot add a dedicated graphics card to that particular laptop of yours. There are only a few select laptops that have a dedicated graphics card that you can switch out. Most of the time you are stuck with what you've got, which would be in this case your Intel integrated graphics.
Not that I necessarily recommend it, but you could possibly squeeze a small amount of juice out of your integrated graphics using MSI afterburner. Google something to help you enable unofficialoverclocking. I've done that on my Laptop with integrated Radeon 6480g graphics and raised it from a stock 512mhz core clock to 1015mhz.
Also, overclocking your CPU would not be a bad idea either. But I do warn you that overclocking and modifying anything in your computer could damage or decrease the lifespan of your components. Just make sure you install something like CoreTemp and make sure to watch the temperature while overclocking anything. Especially since this is a laptop with very limited cooling capabilities. Try to keep it lower than 75c, but the lower the better.
Hope I helped a little bit and good luck with your laptop!