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