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