One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(3,4)(9,10)(11,16)(12,20)(13,17)(14,18)(15,21)(19,23)(22,24) involution — undirected(1,2,6,5)(3,8,4,7)(9,11)(10,13)(12,19)(14,17)(15,23)(16,18)(20,22)(21,24)(25,26,30,31)(27,32,34,28)(29,33,39,40)(35,38,37,36)(1,3,6,4)(2,7,5,8)(12,21)(15,20)(19,24)(22,23)(26,31)(27,34)(33,40)(35,37)(1,4,6,3)(2,8,5,7)(9,12)(10,15)(11,19)(13,23)(14,21)(16,22)(17,24)(18,20)(25,27)(26,32)(28,31)(29,37)(30,34)(33,36)(35,39)(38,40)(1,5,6,2)(3,8,4,7)(9,11)(10,16)(12,19)(13,18)(14,17)(15,22)(20,23)(21,24)(25,28,30,32)(26,27,31,34)(29,38,39,36)(33,37,40,35)(9,13,14,16)(10,17,18,11)(12,22,21,23)(15,19,20,24)(25,29,30,39)(26,33,31,40)(27,35,34,37)(28,36,32,38)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.