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