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