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