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