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