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