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