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)(13,14,19,15)(16,23,26,24)(17,25,21,18)(20,28,22,27)(1,2,4,3)(5,6)(7,10)(8,9)(11,12)(13,15,19,14)(16,24,26,23)(17,18,21,25)(20,27,22,28)(6,9)(10,11)(13,16,25,28,19,26,18,27)(14,20,17,24,15,22,21,23)(5,7,8,12)(6,10,9,11)(13,17,18,14,19,21,25,15)(16,24,27,20,26,23,28,22)(1,3,4,2)(16,26)(20,22)(23,24)(27,28)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.