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