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