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