One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4)(5,9)(6,8)(7,10)(11,12,16,20,17,21,15,25)(13,18,23,26,22,19,14,24)(3,5)(4,7)(6,10)(8,9)(11,13,16,23,17,22,15,14)(12,18,20,26,21,19,25,24)(5,10)(7,9)(11,14,15,22,17,23,16,13)(12,19,20,24,21,18,25,26)(4,8)(7,9)(13,22)(14,23)(18,19)(24,26) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.