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