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