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