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