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