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