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