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