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