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