There are regular buses throughout the day from Lisboa Sete Rios Coach Station to Elvas operated by Rede Expressos.
Unfortunately, the Rede Expressos site is horribly designed, only works in Internet Explorer and is in Portuguese. I do not normally handle requests for this company's timetables, because despite requests to them, they have not made it possible for users of computers without Internet Explorer installed to use their site.
However, I have made an exception in this case and borrowed a Windows machine.
There are departures from Lisboa Sete Rios Coach Station to Elvas at:
08:30
12:00
14:15
15:00
17:30
18:30
19:30
Transit time is about 3 hours and cost circa Euro 13.00
To get to Sete Rios from Lisbon airport take a cab. It should cost between Euros 7 and Euros 10 depending on traffic, number of bags and time of day. There is no metro at the airport and no direct bus service from the Airport to Sete Rios.
