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