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