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