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