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