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