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