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