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