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