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