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