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