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