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