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