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