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