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