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