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