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