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