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