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