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