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)(11,18)(12,13)(14,15)(16,21)(17,22)(19,20)(23,24)(26,31)(32,35)(33,38)(39,40) involution — undirected(2,6)(3,8)(10,15)(12,22)(16,18)(19,23)(25,26,30,31)(27,32,28,35)(29,33,37,38)(34,39,36,40)(1,3)(2,4)(5,8)(6,7)(10,15)(13,17)(16,18)(20,24)(25,27,30,28)(26,32,31,35)(29,36,37,34)(33,40,38,39)(1,3)(2,4)(5,8)(6,7)(9,11,14,21)(10,16,15,18)(12,23,22,19)(13,20,17,24)(25,26)(27,32)(28,35)(29,33)(30,31)(34,39)(36,40)(37,38)(1,4)(2,3)(5,7)(6,8)(9,12)(10,17)(11,19)(13,15)(14,22)(16,20)(18,24)(21,23)(25,28,30,27)(26,32,31,35)(29,36,37,34)(33,39,38,40)(9,13,14,17)(10,12,15,22)(11,20,21,24)(16,23,18,19)(25,29,30,37)(26,33,31,38)(27,34,28,36)(32,39,35,40)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.