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