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