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