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