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