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