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