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