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