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