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