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