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