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