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