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