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