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