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