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