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