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