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