"I didn't want to do an hour here, and an hour there - I wanted to really get stuck in."
Mr Walker gave her free rein, asking only that it was bright and colourful. So Ms Drayton did a rough sketch but filled in the details as she went.
The main colour is orange, and the mural includes mountains Ruapehu and Taranaki, the beach, bush, children, the sun and the school motto - Pride, Honesty and Respect.
Mr Walker said he was delighted with the result.
"TIna is very talented, and we're grateful that she gave her time for this project."
He also wished to thank Bunnings, who donated the paint.