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