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