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