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