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