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