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