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