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