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