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