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