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