At Nascar facilities we used a sheet of polyethylene drop cloth type material,..the design is projected and or free handed if the the artist has the capabilities with a magic marker,.....with this we take and cut half moons alot like the wind slits you would see in a big banner except we remove the whole half moon along the inside edges of areas we need to paint. this serves as a pattern and we go out to the infield and take long gutter nails and or pole barn bars (biggest long assed nail we could find) and stake them down in place in the grass on the infield,...we take an airless and spray a mist coat of white thru these half moon holes and it makes a pattern to use to paint the artwork/logo/advertisment.
edited to add,.. you are going to get your feelings hurt if you try and paint on dirt,......the stuff blows back up in your face when you paint it with a spray gun and it sucks up paint like a sponge,....be prepared to buy four times the amount of paint you would normally use if it were grass and or asphalt,...don't ask me how I came by this pearl of wisdom and I will not tell you any lies,.....