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)(25,26,31,30)(27,32,34,28)(29,37,39,33)(35,36,40,38)(2,3)(6,7)(9,10,14,15)(11,12,16,20)(13,17,21,22)(18,19,23,24)(25,27)(26,32)(28,30)(29,35)(31,34)(33,38)(36,37)(39,40)(1,3,5,2)(4,7,8,6)(13,21)(17,22)(18,23)(19,24)(26,30)(27,34)(33,37)(35,40)(1,4,5,8)(2,6,3,7)(9,11)(10,12)(13,18)(14,16)(15,20)(17,19)(21,23)(22,24)(25,28)(26,27)(29,38)(30,34)(31,32)(33,40)(35,37)(36,39)(9,12)(10,16)(11,15)(13,19)(14,20)(17,23)(18,22)(21,24)(25,29,31,39)(26,33,30,37)(27,35,34,40)(28,36,32,38)(9,13,14,21)(10,17,15,22)(11,18,16,23)(12,19,20,24)(25,30,31,26)(27,28,34,32)(29,37,39,33)(35,36,40,38)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.