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