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