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