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