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