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