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