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