One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4)(5,8)(6,7)(9,10)(11,12)(13,17)(14,16)(15,21)(18,20)(19,23)(22,25)(24,26) involution — undirected(4,7)(8,10)(11,13,17,12,18,14,16,20)(15,21,24,19,25,22,23,26)(3,5,6,9)(4,8,7,10)(11,14,16,12,18,13,17,20)(15,22,23,19,25,21,24,26)(11,15)(12,19)(13,21)(14,22)(16,23)(17,24)(18,25)(20,26) 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.