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