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