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