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