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