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