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