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