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