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