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