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)(11,15)(12,14)(13,16)(17,19)(18,22)(20,21)(23,24)(25,26,29,31)(27,30,34,33)(28,36,37,32)(35,39,40,38)(1,3,5,8)(2,6,7,4)(10,12)(11,17)(16,20)(18,23)(25,27)(26,30)(28,35)(29,34)(31,33)(32,38)(36,39)(37,40)(1,3)(2,6)(4,7)(5,8)(11,17)(13,21)(15,19)(16,20)(26,31)(27,34)(32,36)(35,40) involution — undirected(2,7)(3,8)(9,11)(10,15)(12,19)(13,18)(14,17)(16,22)(20,24)(21,23)(25,26)(27,33)(28,36)(29,31)(30,34)(32,37)(35,38)(39,40) involution — undirected(1,3)(2,4)(5,8)(6,7)(9,12,14,10)(11,15,17,19)(13,20,21,16)(18,22,23,24)(25,28,29,37)(26,32,31,36)(27,35,34,40)(30,38,33,39)(1,4)(2,3)(5,6)(7,8)(9,13,14,21)(10,16,12,20)(11,18,17,23)(15,22,19,24)(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.