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