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