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