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