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