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