Check your 'Graduation' tab to see where your graduation is at. The Graduation Office has to to receive confirmation from your Faculty that you have completed the requirements of your programme. You'll receive a message in MyWaikato (and an automatic email alert) when things have progressed.
If it is four weeks (or less) before the graduation ceremony and you have still not heard anything, please contact the Graduation Office directly on 0800 WAIKATO or info@waikato.ac.nz