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