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