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