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