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