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