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