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