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