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