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