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