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)(11,16)(12,18)(13,19)(14,20)(15,17)(21,24)(22,23)(25,26,32,36)(27,37,40,33)(28,29,30,34)(31,38,39,35)(9,11)(10,16)(12,13)(14,17)(15,20)(18,19)(21,22)(23,24)(25,27,32,40)(26,33,36,37)(28,35,30,38)(29,39,34,31)(1,2)(3,5)(4,6)(7,8)(10,17)(11,20)(13,21)(18,23)(25,28,32,30)(26,34,36,29)(27,38,40,35)(31,33,39,37)(3,7)(5,8)(9,12)(10,18)(11,21)(13,20)(14,19)(15,22)(16,24)(17,23)(25,29)(26,28)(27,39)(30,36)(31,40)(32,34)(33,35)(37,38) involution — undirected(1,3,4,7)(2,5,6,8)(9,13,15,21)(10,19,17,24)(11,12,20,22)(14,23,16,18)(25,30,32,28)(26,34,36,29)(27,38,40,35)(31,37,39,33)(1,2)(3,5)(4,6)(7,8)(9,14)(10,11)(12,19)(13,23)(15,16)(17,20)(18,21)(22,24)(25,31,32,39)(26,35,36,38)(27,29,40,34)(28,33,30,37)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.