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