I think what your looking for is this page:

http://www.intrade.com/jsp/intrade/contractSearch/searchPageBuilder.jsp?grpID=3385

Where grpID is one of the grpID's in:

http://www.intrade.com/jsp/graph/groups.js?113253315

I'm not sure if the number on the end changes. I'm also not sure if they built it this way to make it more difficult for you to mine their data, you might want check their rules.

HTH,
Steve