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