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