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