One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,10)(8,9)(11,12) involution — undirected(6,9)(10,12)(13,14)(15,22)(16,20)(17,26)(18,21)(19,23)(24,25)(27,28) involution — undirected(2,4)(13,15,18,24)(14,19,21,28)(16,25,26,22)(17,27,20,23)(5,7,8,11)(6,10,9,12)(13,16,18,26)(14,20,21,17)(15,19,24,28)(22,23,25,27)(14,16)(17,20)(19,25)(21,26)(22,28)(23,27) 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.