Go to Inbox and click on a fax number in which you have received the fax. You can see the Fax History of received faxes there.
You can follow this navigation to reach the destination: Inbox -> Fax Number -> Received
You will find a PDF icon in the right hand side of each fax log. Click on that and your fax will open in a new window. You can download and save it in your system or print it directly from there.