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