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