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