I've had success marking grass in the past using weedkiller to scorch out the marks you need, then highlight them with cement dust. They'll keep in quite well but during the growing season, you'll need to keep up with it. I suggest a 20lit backpack and a hand lance.
One word, though. It's amazingly difficult to see what you're doing at ground level, so make out a plan, then mark out where you need the marks with cones or similar. They'll need to be MUCH bigger than you think. In the UK, use CAP 168 for a guide to dimensions. If you're in Canada, then I'm sure you can still access this UK document, or perhaps Transport Canada publishes similar.
TOO