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