There are plenty of buses daily from Lisbon to Albufeira even on Sundays.
There is are 17:00 and 19:00 departures from Lisbon Gare Oriente Bus Station (ten minutes by cab from the Airport), operated by Renex, and arriving in Albufeira at 20:15 and 22:15 respectively.
There is a service operated by Rede Expressos from Lisbon Sete Rios Bus Station departing at 18:30 and arriving 21:10.
