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