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