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