No shuttle bus available at the airport at that time. So you can consider to share taxi with others. Better to find the Shunde taxi which are going back from Guangzhou Airpport. It is much cheaper. If not, you should take airport bus to the city center and stay one night. The ealiest bus to Daliang can be found at Guangdong provincial bus Station nearby Guangzhou Railway Station, before 6am. Or you can stay nearby the airport and take the first shuttle bus at Guangzhou Airport to Shunde Daliang Terminal at 7:50.