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