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