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