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