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