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