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