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