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