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