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