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