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