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