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