Hi,
If you have been working in SRM since long, I am sure you would not be interested in normal procurement cycle, which remains same in Ariba (apart from look and feel). Therefore, I would suggest you to explore admin area as this will give you deep understanding of master data handling, workflow and processes, notifications, user management, supplier management etc.
Also, as Pramod rightly pointed out there are upstream modules as well where you may find value of Ariba. Just go with the flow.
Regards,
Ravi Pachauri