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