You can take a train K259. It departs from Guangzhou North at 10:20 and reach Guangzhou East at 11:13, totally 53 minutes.
Besides, you can also take public buses. Walking to Huadu Bus Terminal and take bus No. 616 at the departure stop and get off at the terminal (Tianhe Bus Terminal). And then transfer to bus No. 39 or 884 and get off at the Guangzhou East. It will take about 1 to 1.5 hours, depending on the traffic condition.