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