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