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