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