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