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