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)(11,14)(12,19)(13,15)(16,21)(17,23)(18,24)(20,22)(25,26,30,31)(27,32,37,33)(28,34,39,29)(35,36,38,40)(1,3,4,7)(2,5,6,8)(9,11,13,17)(10,14,15,23)(12,20,21,18)(16,24,19,22)(26,31)(29,34)(32,33)(36,40)(1,2)(3,5)(4,6)(7,8)(10,15)(11,17)(16,19)(18,20)(25,27,30,37)(26,32,31,33)(28,38,39,35)(29,36,34,40)(9,10)(11,14)(12,16)(13,15)(17,23)(18,22)(19,21)(20,24)(25,27)(26,33)(28,35)(29,36)(30,37)(31,32)(34,40)(38,39) involution — undirected(1,3)(2,5)(4,7)(6,8)(9,11)(10,14)(12,18)(13,17)(15,23)(16,22)(19,24)(20,21)(25,28)(26,34)(27,35)(29,31)(30,39)(32,36)(33,40)(37,38) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,12)(10,16)(11,18)(13,21)(14,22)(15,19)(17,20)(23,24)(25,29,30,34)(26,28,31,39)(27,36,37,40)(32,38,33,35)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.