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