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