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