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