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