Undergraduate / How to write SoP for a Design University [4]

Hi!
I'd would like to write a statement of purpose at Design University. At present I've a B.A degree and I hope I can study Master of Design at Monash Unviersity. My major is visual communication. I'm working print ad, indentify brand, package and I really want to apply Master of Design (coursework). However I don't know how to start a SoP? Can you help me please ?

Thank so much