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