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