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