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