Pole zero plot, normalizing frequency response plot?
For the frequency axis, you're going to have to normalize by $\pi$ to plot digital frequencies in $[0,\pi]$.

For the magnitude axis, normalize by $\mathrm{max}\left(|H\left(e^{i\omega}\right)|\right)$.

I'm surprised you weren't asked to plot magnitude response in dB (a logarithmic axis).