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