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