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