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