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