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