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