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