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