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