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