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