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