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