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