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