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