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