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