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