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