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