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