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