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