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