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