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