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