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