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