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