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