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