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