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