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