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