abstract algebra - Multiplication table of a Galois group?

I'm looking at the polynomial $x^4 − 4x^2 + 16$. I know that its roots are
$1\pm\sqrt{3}$ and so its normal field extension is $\mathbb Q(i, \sqrt{3})$.

However, I am also asked to give a multiplication table for the Galois group. What will that look like? What will be its rows and columns?)

(I am practicing for an exam)