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