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)(13,14,18,20)(15,22,25,24)(16,23,21,17)(19,27,28,26)(5,7,8,11)(6,9,10,12)(13,15,23,27,18,25,17,26)(14,19,16,24,20,28,21,22)(6,10)(9,12)(14,20)(16,21)(19,28)(22,24) involution — undirected(2,4)(13,16,17,14,18,21,23,20)(15,24,26,19,25,22,27,28)(15,25)(19,28)(22,24)(26,27) 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.