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