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