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