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