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