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