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