There is no bus directly to Shanghai from Hangzhou airport. At Hangzhou East Bus Station, many buses to Shanghai are available, but the last bus is departing at 19:00. Anyway, here are two options for you: 1) take a taxi to Hangzhou Chengzhan Railway Station, and then take the train K528 to Shanghai, leaving Hangzhou at 02:08; 2) take a taxi to the city center, and stay one night there, next day take the bus or train to Shanghai directly.

You can take a train at Xiaoshan Railwasy Station (also called Hangzhou South Railway Station) which is about 20 km from Hangzhou Airport, much nearer than the other railway stations of Hangzhou. There are several mid night trains going to Shanghai.