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