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