I was not sure if I ask this question here or not.

But while I was naming the characters I noticed the game-hand wasn't moving around as fast as I was moving the mouse.
I tried to look for an option to change it but can't find any in the setting.

So is there an option for mouse speed sensitivity? and if so where is it located?

Greetings WARIO88,

Unfortunately, there is no in-game option to change mouse sensitivity, however things might change in future.
In the meantime you can change mouse sensitivity by following these steps:

Click "Start Menu" (windows key)
Open "Control Panel"
Open "Mouse"
Click on "Pointer Options" tab
Adjust the slider of "Select Pointer Speed" to suit your needs
Click "Apply"
Click "OK"

Saucex