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