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