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