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