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