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