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