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