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