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