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