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