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