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