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