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