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