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