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