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