Travel to Henquin Chimelong Ocean Kingdom from Macau

I am a United States citizen with a US passport. I will be staying in Macau, but would like to take a day trip to Hengqin Chimelong Ocean Kingdom on Hengqin Island, Guangdong Province, returning to Macau on the same day. I will be taking a bus or taxi from Macau to the Ocean Kingdom. Am I eligible for a 72 hour transit visa and if so, where do I get it?