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