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