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