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