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