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