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