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