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