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