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