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