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