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