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