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