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