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