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