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