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