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