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