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