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