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