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)(11,12,16,20)(13,21,23,17)(18,22,24,19)(25,26)(27,28)(29,37)(30,31)(32,33)(34,38)(35,39)(36,40)(1,3,4,7)(2,5,6,8)(9,11)(10,12)(13,18)(14,16)(15,20)(17,19)(21,22)(23,24)(26,31)(27,33)(34,37)(35,40)(1,2)(3,5)(4,6)(7,8)(10,15)(11,16)(17,21)(18,24)(25,27,30,33)(26,32,31,28)(29,35,38,40)(34,39,37,36)(9,10)(11,12)(13,17)(14,15)(16,20)(18,19)(21,23)(22,24)(25,28,30,32)(26,33,31,27)(29,36,38,39)(34,40,37,35)(1,3)(2,5)(4,7)(6,8)(9,12)(10,16)(11,15)(13,22)(14,20)(17,18)(19,23)(21,24)(25,26)(27,32)(28,33)(29,34)(30,31)(35,39)(36,40)(37,38) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,13)(10,17)(11,18)(12,19)(14,23)(15,21)(16,24)(20,22)(25,29)(26,34)(27,35)(28,36)(30,38)(31,37)(32,39)(33,40) 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.