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