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