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