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