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