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