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