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