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