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