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