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