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