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