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