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