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)(15,23)(16,19)(17,20)(18,22)(21,26)(24,27)(25,28) involution — undirected(1,2)(3,4)(6,9)(10,12)(13,15,19,26)(14,21,16,23)(17,28,22,24)(18,25,20,27)(5,7,8,11)(6,10,9,12)(13,16,20,17,19,14,18,22)(15,24,25,21,26,28,27,23)(2,4)(13,17,20,14,19,22,18,16)(15,21,25,28,26,23,27,24)(6,9)(10,12)(13,18,19,20)(14,17,16,22)(15,25,26,27)(21,28,23,24)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.