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