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