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