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