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