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