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