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