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